NOAA REPORTS JULY COOLER, WETTER THAN AVERAGE IN THE EAST, HOT IN
THE WEST

In
much of the East, rainfall was unusually heavy and average monthly
temperatures were generally cooler than average. Record and near-record
heat affected a large part of the western United States in July, and
below-average precipitation contributed to persistent or worsening
drought conditions throughout much of the region, according to scientists
at the National Oceanic and Atmospheric Administration’s (NOAA)
National Climatic Data Center in Asheville, N.C. NOAA is an agency
of the Commerce Department.

NOAA scientists report the average temperature
for the contiguous United States in July (based on preliminary data)
was 75.7°F (24.3°C), which was 1.4°F (0.8°C) above
the 1895-2003 mean. It was the twelfth-warmest July since national
records began in 1895.

Numerous daily and monthly all-time records
were established across the West, as a dominant high pressure area
persisted throughout the month. The monthly mean temperature in every
western state – except California – was much warmer than
average, and Idaho had its warmest July on record. In Phoenix, Las
Vegas, Cheyenne, Wyo. and Grand Junction, Colo., July 2003 was the
warmest month on record.

The Western warmth contrasted sharply
with cooler-than-average temperatures in much of the East. Twelve
states from Mississippi to Pennsylvania were significantly cooler
than average. Upper-level winds in the atmosphere pushed unusually
far south in the eastern United States in July, leading to generally
cooler and wetter-than-average conditions. This continued a pattern
that has persisted for much of the spring and summer.

Seventeen states east of the Mississippi
were significantly wetter than average in July, and May-July was the
wettest late spring-mid summer period in four states (Alabama, Tennessee,
Virginia and Ohio). The same three-month period was the second wettest
on record in four other states (Georgia, South Carolina, West Virginia
and Indiana).

While wetter-than-average conditions
covered much of the East, the same ridge of high pressure that brought
record heat to the West also resulted in below average precipitation
in many states. Fourteen states west of the Mississippi were significantly
drier than average for July. Four of those states (Kansas, Colorado,
Wyoming and Montana) were much drier than average, and New Mexico
had its driest July on record.

The heat and lack of precipitation occurred
in many of the same states that have experienced drought for the past
three to five years. At the end of July, 70 percent of the West was
in moderate to extreme drought, based on a widely used measure of
drought, the Palmer Drought Index. This was an increase of 11 percent
since June and 21 percent since the end of May, continuing the reversal
of a short-term trend toward improving conditions that had begun late
last year. The most widespread drought on record occurred in July
1934 when moderate to extreme drought affected 97 percent of the West.
The persistence of unusually warm and dry conditions over the last
several years has created conditions that rival those experienced
during the drought years of the 1930s and 1950s in parts of the West.

Globe:

The global average temperature was second warmest on record, and a
damaging heat wave affected much of Europe. the average global surface
temperature for combined land and ocean surfaces during July 2003
(based on preliminary data) was 0.9° F (0.5° C) above the
1880-2002 long-term mean, the second-warmest July since 1880 (the
beginning of reliable instrumental records). The warmest July on record
occurred in 1998. Since 1900, global surface temperatures have risen
at a rate of 1.0° F/century (0.6° C/century), but the rate
has increased to approximately three times the century-scale trend
since 1976.

Land surface temperatures for July were
the third warmest in the historical record. Much warmer than average
temperatures were widespread across Europe, which was affected by
a severe heat wave during the month. Daily high temperatures routinely
exceeded 90° F (32° C), and at times 100° F (38° C),
across many areas from France and Switzerland southeastward across
the Mediterranean region.

NOAA’s Satellite and Information
Service is the nation’s primary source of space-based meteorological
and climate data. It operates the nation's environmental satellites,
which are used for weather forecasting, climate monitoring and other
environmental applications such as fire detection, ozone monitoring
and sea surface temperature measurements.

The
agency also operates three data centers, which house global databases
in climatology, oceanography, solid earth geophysics, marine geology
and geophysics, solar-terrestrial physics, and paleoclimatology. To
learn more about NOAA’s Satellite and Information Service, please
visit http://www.nesdis.noaa.gov.

NOAA
is dedicated to enhancing economic security and national safety through
the prediction and research of weather and climate-related events
and providing environmental stewardship of the nation’s coastal
and marine resources. To learn more about NOAA, please visit: http://www.noaa.gov.